1. Field of the Invention
The present invention relates to a wireless communication system and, more particularly, to a method and apparatus for generating a traffic indicator map.
2. Background Art
The Wireless Local Area Network (hereinafter referred to as WLAN) technology standard has been established by the IEEE (Institute of Electrical and Electronic Engineers) 802.11 Standardization Association. Among the IEEE 802.11 standards, IEEE 802.11a/b uses a frequency band of 2.4 GHz or 5 GHz, so as to provide a transmission (or transport) efficiency of 11 Mbps (IEEE 802.11b) or 54 Mbps (IEEE 802.11a). IEEE 802.11g may provide a transmission efficiency of 54 Mbps by applying an OFDM (Orthogonal Frequency Divisional Multiplexing) scheme. Additionally, IEEE 802.11n may provide a transmission efficiency of 300 Mbps by applying a MIMO-OFDM scheme. Furthermore, the IEEE 802.11n may also provide a maximum transmission efficiency of 600 Mbps by using a maximum channel bandwidth of 40 Mhz.
In accordance with the enlargement of base of the WLAN and the variation in the applications using the WLAN, the request for a new WLAN system supporting more enhanced performance than the performance supported by the IEEE 802.11n system. A VTH (Very High Throughput) WLAN system corresponds to one of the most recently proposed IEEE 802.11 WLAN systems for supporting a data processing rate of 1 Gps or more. In order to establish standardization of the VHT WLAN system, research on schemes and methods, such as 8×8 MIMO for the standardization of the VHT WLAN system, a channel bandwidth of 80 MHz or higher, a PLCP (Physical Layer Convergence Procedure) format for efficiently supporting the co-existence of each station, such as VHT-STA, HT-STA, and Legacy-STA, and so on, is being thoroughly carried out in IEEE 802.11ac operation groups.
Additionally, standardization regulating the WLAN in a TV white space is being realized with IEEE 802.11af. The TV white space includes a channel, which is allocated to a broadcast channel, which is authorized for the usage of a cognitive radio device, and generally refers to a band of 512-698 MHz.